login script to database

[Peter.....]

Hi all.

I want to make a login script( using python) to a homepage.
The password and name is stored in a PostgreSQL database, so I have to go to 
connect to the database ( I know how to do that )
but I dont know how to write a login script in python and how to look if the 
password and name entered is the same as in the database, if it is I want to 
link to a webpage www.webpage.com if it isnt I want it to write a message 
like " Wrong password entered "

Can any help me out :D

Thanks for your time..